5.18. Secret codes.
Look at Kevin McCarron’s Visible Spectrum image page
[http://faculty.oprfhs.org/kmccarron/HOU/color/spectrum.html] and look
through red, green and blue filters to view it. Which filter shows the
“secret message that McCarron hid in the words?” Then look at the
rainbow/spectrum at the top of the page through different filters. See
if you can figure out why one color filter works best to reveal this
secret message. Then, once you think you’ve figured it out, try making
your own secret message will colored pens, crayons, or computer tools to
see if your theory is correct.

5.19. What is an object’s color?
What happens when you look at a colored object through different color
filters? Objects reflect certain colors of light, and that’s why they
look that color.

5.20. Color Astronomy. Look at images of
astronomical objects (posters, slides or Kevin McCarron’s HOU Color
Page) through the different filters. What are we seeing?